1. Field of the Invention
The present invention relates generally to foam generation systems used in the insulation and/or shading of transparent structures such as greenhouses, atriums, etc.
2. Description of the Prior Art
Building structures having cavities formed between double light transmitting roof or wall membranes for receiving degradable or replaceable foam insulation are known. The roof and wall cavities can be periodically filled with degradable foam to provide shading or thermal insulation. However, when it is desired to let the light pass through the building envelope in order to take advantage of the solar energy, the foam can be readily dissolved and removed from the cavities. Examples of such buildings can be found in U.S. Pat. Nos. 3,672,184 and 4,562,674.
The foam generators used in the above mentioned patents for filling the roof and wall cavities with foam bubbles essentially consist of a fan spraying a soap solution onto a screen at the entry of the wall and roof cavities. One drawback of such large fan system is that it is difficult to adapt to existing structure. Such particular systems require that the thickness in the cavity between the membranes be large enough to accommodate the fan generator. Also, the foam generated with this type of system cannot be placed anywhere desired. This creates additional difficulties for more complex roofing structures. Finally, large fan foam generator generates foam characterized by large bubbles and thus having a lower insulation value.